It is well-known that e$^+$e$^-$ colliders have the power to with certainty exclude or discover any SUSY model that predicts a Next to lightest SUSY particle (an NLSP) that has a mass up to slightly below the half the centre-of-mass energy of the collider. Here, we present an estimation of the power of present and future hadron colliders to extend the reach of searches for SUSY, with particular emphasis whether it can be claimed that either discovery or exclusion is {\it guaranteed} in a region of LSP and NLSP masses - no set of values of the other SUSY could change the conclusion. A scan over SUSY parameter space was done, only requiring that the NLSP was a bosino - the hardest case - with mass not larger than a few TeV. The mass-spectrum, cross-sections and decay branching ratios found in this region were confronted with projections of sensitivity at future hadron colliders. In our conclusions we weigh in the maturity of the analysis the projections are based upon. The conclusion is that although future hadron colliders have a large discovery-reach, i.e. potential to discover {\it some} SUSY model, hardly any models with low-to-medium LSP-NLSP mass-differences can be excluded with certainty. The models that are expected to be excluded/discovered are, on one hand, those with mass-differences larger than those allowed by models with GUT-scale $M_1$-$M_2$ unification, and on the other hand, a tiny region where the mass-difference is so small that the NLSP decays in the tracking volume of the detectors. Excluding the latter possibility does not, however, allow to exclude the possibility of a Wino or Higgsino LSP: at any value of the LSP mass, we could identify models where the NLSP lifetime would be too short for a signal to be seen.
We present a summary of results for SUSY Simplified Model searches at future proton colliders: the 14 TeV LHC as well as a 33 TeV proton collider and a 100 TeV proton collider. Upper limits and discovery significances are provided for the gluino-neutralino (for both light and heavy flavor decays), squark-neutralino, and gluino-squark Simplified Model planes. Events are processed with the Snowmass combined detector and Standard Model backgrounds are computed using the Snowmass samples. We place emphasis on comparisons between different collider scenarios, along with the lessons learned regardin…
Tau tau fusion to light h and heavy H,A Higgs bosons is investigated in the Minimal Supersymmetric Standard Model (MSSM) at a photon collider as a promising channel for measuring large values of tan(beta). For standard design parameters of a photon collider an error close to unity, uniform for tan(beta) above 10, may be expected, improving on complementary measurements at LHC and e+e- linear colliders.
Theoretical overview on phenomenology of Higgs boson and SUSY Higgs boson at a future linear collider experiment is given as a Higgs and SUSY Higgs working group summary report for LCWS 2000.
Considering the constraints from collider experiments and dark matter detections, we investigate the SUSY effects in the Higgs productions $e^+e^- \to Zh$ at an $e^+e^-$ collider with a center-of-mass energy above 240 GeV and $γγ\to h \to b\bar{b}$ at a photon collider with a center-of-mass energy above 125 GeV. In the parameter space allowed by current experiments, we find that the SUSY corrections to $e^+e^- \to Zh$ can reach a few percent and the production rate of $γγ\to h \to b\bar{b}$ can be enhanced by a factor of 1.2 over the SM prediction. We also calculate the exotic Higgs production…
I summarise the activities of the different members of the SUSY working group. There have been two major areas of activity: 1) precision measurement of the SUSY particle masses/couplings and hence those of the SUSY model parameters, 2) investigations into SUSY searches at \eplem, \gamgam, $\game$ and $\emem$ colliders, in the nonstandard scenarios such as explicit CP violation, R-parity violation and Anomaly Mediated Supersymmtery Breaking. In addition there have been studies which looked at the effect of `large' extra dimensions at the various colliders mentioned above.
The theoretical status of Higgs boson and supersymmetric particle production at hadron colliders is reviewed with particular emphasis on recent results and open problems.
After a brief review of the Minimal Supersymmetric Standard Model (MSSM) and specifically the Minimal Supergravity Model (SUGRA), the prospects for discovering and studying SUSY at the CERN Large Hadron Collider are reviewed. The possible role for a future Lepton Collider --- whether $μ^+μ^-$ or $e^+e^-$ --- is also discussed.
Results are presented for a variety of SUSY Simplified Models at the 14 TeV LHC as well as a 33 and 100 TeV proton collider. Our focus is on models whose signals are driven by colored production. We present projections of the upper limit and discovery reach in the gluino-neutralino (for both light and heavy flavor decays), squark-neutralino, and gluino-squark Simplified Model planes. Depending on the model a jets + MET, mono-jet, or same-sign di-lepton search is applied. The impact of pileup is explored. This study utilizes the Snowmass backgrounds and combined detector. Assuming 3000 fb^{-1} …
We present an outlook for possible R-parity violating SUSY search at gamma-proton and gamma-electron colliders. Single production of third generation slepton/sneutrino through the lambda'-ijk couplings at a gamma-p collider is investigated and compared with the results of the resonant sfermion productions at the existing colliders. Also single sneutrino production at a future gamma-electron collider through the lambda(ijk) couplings is disussed.
The determination of the full SUSY QCD corrections to the production of squarks, gluinos and gauginos at hadron colliders is reviewed. The NLO corrections stabilize the theoretical predictions of the various production cross sections significantly and lead to sizeable enhancements of the most relevant cross sections. We discuss the phenomenological consequences of the results on present and future experimental analyses.
SPheno is a program that accurately calculates the supersymmetric particle spectrum within a high scale theory, such as minimal supergravity, gauge mediated supersymmetry breaking, anomaly mediated supersymmetry breaking, or string effective field theories. An interface exists for an easy implementation of other models. The program solves the renormalization group equations numerically to two--loop order with user-specified boundary conditions. The complete one--loop formulas for the masses are used which are supplemented by two--loop contributions in case of the neutral Higgs bosons and the m…
We examine the single-photon processes in the frame work of supersymmetric models at future e+e- linear colliders. According to the recent experimental achievement, the optimistic polarization degrees for both electron and positron beams are taken into account to enhance the signal-to-noise ratio revealing the observable difference between supersymmetry breaking models. The minimal supergravity model and the minimal SU(5) grand unified model in gaugino mediation have been examined as examples. We see that after several years of accummulating data, the difference of the number of single-photon …
After summarising very briefly the key features of different model predictions for sparticle masses and their relation with the supersymmetry (SUSY) breaking scales and parameters, I discuss the capabilities of an $e^+ e^-$ Linear Collider (LC) with $\sqrt{s} \geq$ 500 GeV for precision measurements of sparticle properties. Then I focus on the lessons one can learn about the scale and mechanism of SUSY breaking from these measurements and point out how LC can crucially complement and extend the achievements of the LHC. I end by mentioning what would be the desired extensions in the type/energy…
In the Minimal Supersymmetric Model (MSSM) the hitherto unconstrained flavor mixing between top-squark and charm-squark will induce the flavor-changing neutral-current (FCNC) interaction between top quark and charm quark, which then give rise to various processes at the next generation linear collider (NLC), i.e., the top-charm associated productions via $e^+ e^-$, $e^- γ$ and $γγ$ collisions as well as the top quark rare decays $t \to c V$ ($V=g$, $γ$ or $Z$). All these processes involve the same part of the parameter space of the MSSM. Through a comparative analysis for all these processes a…
After a brief introduction to SUSY I discuss the missing-p_T signature for superparticles from R-parity conservation and the multilepton signature, which follows from their cascade decay. The GUT and SUGRA constraints on the SUSY mass parameters are discussed along with the resulting SUSY signals at LHC. Finally I consider the effect of relaxing the SUGRA constraint on these signals.
We evaluate the contribution of SUSY-QCD to top-charm associated production at next generation linear colliders. Our results show that the production cross section of the process $e^+e^-\to t\bar c{or}\bar t c$ could be as large as 0.1 fb, which is larger than the prediction of the SM by a factor of $10^8$.
While SUSY particles, if they exist at the TeV-scale, will be discovered at the Tevatron or the LHC, the determination of the SUSY-breaking scenario and its free parameters will require additional information, e.g. from a future International Linear Collider. We point out that such information, in particular on SUSY-particle mixing and the associated soft SUSY-breaking parameters, can also be obtained from measurements at existing or future polarized hadron colliders, since the polarization of initial-state quarks, transmitted through weak gauge bosons or squarks, can be strongly correlated wi…
Properties of Dirac neutralinos and the corresponding EW scalar gauge bosons, as predicted by the N=1/N=2 hybrid supersymmetric model, and prospects for their discovery at colliders are discussed.
This talk presents the detection issues for the lightest slepton \tildeτ_1 at a future e+e- TeV collider given the dark matter constraints set on the SUSY mass spectrum by the WMAP results. Two methods for measuring its mass m_{\tildeτ_1} and the resulting precision on the dark matter density are briefly discussed in the SUSY mSUGRA scenario with R-parity conservation when the mass difference between m_{\tildeτ_1} and that of the lightest neutralino is small (a few GeV). The analysis is performed with TESLA parameters in both head-on and crossing angle modes.
We investigate ττfusion to light h and heavy H and A Higgs bosons in the Minimal Supersymmetric Standard Model (MSSM) at a photon collider as a promising channel for measuring large values of tan(beta). For standard design parameters of a photon collider an error Δtan(beta) \sim 1, uniformly for tan(beta) \gsim 10, may be expected, improving on complementary measurements at the LHC and e+e- linear colliders.
In this talk, I discuss some aspects of Higgs searches at future colliders, particularly comparing and contrasting the capabilities of LHC and Next Linear Collider (NLC), including the aspects of Higgs searches in supersymmetric theories. After this, I will discuss how the search and study of sparticles other than the Higgs can give information about the parameters of the Minimal Supersymmetric Standard Model (MSSM).
We analyze the next-to-leading order SUSY-QCD corrections to the production of Higgs particles at hadron colliders in supersymmetric extensions of the Standard Model. Besides the standard QCD corrections due to gluon exchange and emission, genuine supersymmetric corrections due to the virtual exchange of squarks and gluinos are present. At both the Tevatron and the LHC, these corrections are found to be small in the Higgs-strahlung, Drell-Yan-like Higgs pair production and vector boson fusion processes.
The like sign dileptons provide the most promising signature for superparticle search in a large category of $R$-parity violating SUSY models. We estimate the like sign dilepton signals at the Tevatron collider, predicted by these models, over a wide region of the MSSM parameter space. One expects an unambiguous signal upto a gluino mass of $200 - 300$ GeV ($\geq 500$ GeV) with the present (proposed) accumulated luminosity of $\sim 0.1~(1)~{\rm fb}^{-1}$.
We explore the physics of the general CP-conserving MSSM with Minimal Flavor Violation, the pMSSM. The 19 soft SUSY breaking parameters are chosen so to satisfy all existing experimental and theoretical constraints assuming that the WIMP is the lightest neutralino. We scan this parameter space twice using both flat and log priors and compare the results which yield similar conclusions. Constraints from both LEP and the Tevatron play an important role in obtaining our final model samples. Implications for future TeV-scale $e^+e^-$ linear colliders(LC) are discussed.
Supersymmetry predicts the identity of Yukawa and gauge couplings in the QCD sector: quark-squark-gluino = squark-squark-gluon = quark-quark-gluon. We examine whether the quark-squark-gluino Yukawa coupling can be determined, by methods complementary to LHC, by analyzing squark-gluino final states at a TeV e+e- collider.
One of the useful features of muon colliders is the naturally narrow spread in beam energies. Measurements of threshold cross sections then become a prime candidate for precision measurements of particle masses, widths, and couplings as well as determining particle spin. We describe the potential for measuring cross sections near threshold in supersymmetric theories.
We calculate the SUSY-QCD corrections to the inclusive total cross sections of the associated production processes $pp\to W^{\pm}H^{\mp}+X$ in the Minimal Supersymmetric Standard Model(MSSM) at the CERN Large Hadron Collider(LHC). The SUSY-QCD corrections can increase and decrease the total cross sections depending on the choice of the SUSY parameters. When $μ<0$ the SUSY-QCD corrections increase the leading-order (LO) total cross sections significantly for large tan$β$ ($\sim 40$), which can exceed 10% and have the opposite sign with respect to the QCD and the SUSY-EW corrections, and thus ca…
We consider the production of neutralino, chargino, and charged Higgs boson pairs in the MSSM framework at future $e^+e^-$ colliders. We show that, for c.m. energies in the one TeV range and in a ``moderately'' light SUSY scenario, a combined analysis of the slopes of these production cross sections could lead to a strong consistency test involving the soft supersymmetric breaking parameters $M_1$, $M_2$, the Higgsino parameter $μ$, and $\tanβ$.
The lightest superparticle in the MSSM is expected to be a Bino, Higgsino or Wino. We consider the dark matter abundance constraint on these LSP scenarios in the minimal SUGRA and AMSB models. We discuss the resulting collider signals for the Bino LSP at LHC and the Higgsino and Wino LSP at CLIC. The Bino, Higgsino and Wino LSP signals in dark matter experiments are also discussed briefly. We conclude with a discussion of these LSP scenarios in nonminimal SUSY models.
Grand Unified Theories (GUTs) are attractive candidates for more fundamental elementary particle theories. They can not only unify the Standard Model (SM) interactions but also different types of SM fermions, in particular quarks and leptons, in joint representations of the GUT gauge group. We discuss how comparing predictive supersymmetric GUT models with the experimental results for quark and charged lepton masses leads to constraints on the SUSY spectrum. We show an example from a recent analysis where the resulting superpartner masses where found just beyond the reach of LHC run 1, but ful…
If supersymmetry is spontaneously at a low energy scale then the resulting gravitino would be very light. The interaction strength of the longitudinal components of such a light gravitino to electron-selectron pair then becomes comparable to that of electroweak interactions. Such a light gravitino could modify the cross-section for $e^_L e^_R-->\tilde {e}_L\tilde {e}_R$ from its MSSM value. Precision measurement of this cross-section could therefore be used to probe the low energy SUSY breaking scale.
This paper presents the detection issues for the lightest slepton \tildeτ_1 at a future e^+e^- TeV collider given the dark matter constraints set on the SUSY mass spectrum by the WMAP results. It intends to illustrate the importance of an optimal detection of energetic electrons in the very forward region for an efficient rejection of the γγbackground. The TESLA parameters have been used in the case of head-on collisions and in the case of a 10, mrad half crossing angle.
The extraction of the parameters of the supersymmetric Lagrangian is discusse d. Particular emphasis is put on the rigorous treatment of experimental and theo retical errors. While the LHC can provide a valuable first estimate of the parameters, the combination of LHC and ILC will be nece ssary to determine with high precision the parameters of the MSSM.
The sensitivity of future electron-proton colliders, the LHeC and FCC-eh, to weakly-produced supersymmetric particles is evaluated in this article. Supersymmetric scenarios where charginos ($\tildeχ_1^{\pm}$) and neutralinos ($\tildeχ_1^{0}$ and $\tildeχ_2^{0}$) are nearly degenerate in mass are considered. Two sets of models, which differ in the mass of sleptons ($\tilde{\ell}$), are studied. Under the hypothesis that slepton masses are at the multi-TeV scale (``decoupled'' scenario), the production processes for charginos and neutralinos at $ep$ colliders, $p\, e^- \to j\, e^-\, \tildeχ \til…
The lightest neutralino in supersymmetric models with conserved R-parity is an attractive candidate for non-luminous matter in the universe. If relic neutralinos are indeed present as dark matter in our galaxy, they can be directly detected in scattering experiments. This could serve as an independent search channel for supersymmetry complementary to collider experiments. I compare the sensitivity of direct detection experiments with the reach for supersymmetry at collider facilities in the framework of the minimal supergravity model.
If supersymmetry is dynamically broken at a low scale ($M_{susy}$), within a few orders of magnitude of the weak scale, then the lightest supersymmetric partner is the gravitino and the next to lightest supersymmetric partner is a neutralino $χ^0_1$ with mass $m_{χ^0_1}$, which can decay into a photon ($γ$) plus a gravitino ($\widetilde{G}$). We study the detection of $e^{-}e^{+}\rightarrow χ^0_1 χ^0_1 \rightarrow γ\widetilde{G}γ\widetilde{G}$ at the proposed Linear Collider, and find the range of the parameters $M_{susy}$ and $m_{χ^0_1}$ that can be accessible with a right-hand polarized elec…
Supersymmetry predicts that gauge couplings are equal to the corresponding gaugino-sfermion-fermion Yukawa couplings. This prediction can be tested for the QCD sector of the MSSM by studying the processes eplus+eminus -> squark+antisquark+gluon and eplus+eminus -> squark+antiquark+gluino at a future linear collider. We present results for these processes at next-to-leading order in alpha_s in the framework of the MSSM. We find sizable SUSY-QCD corrections. The renormalization scale dependence is significantly reduced at next-to-leading order.
\susy23 is a Monte-Carlo package for generating supersymmetric (SUSY) processes at $e^+e^-$ colliders. Twenty-three types of SUSY processes with 2 or 3 final state particles at tree level are included in version 2.0. {\susy23} addresses event simulation requirements at $e^+e^-$ colliders such as LEP. Matrix elements are generated by GRACE with the helicity amplitude method for processes involving massive fermions. The phase space integration of the matrix element gives the total and differential cross sections, then unweighted events are generated. Sparticle widths and decay branching ratios a…
Several results obtained within the SUSY group of the ECFA/DESY linear collider study are presented: (i) a possibility to determine tan beta and the trilinear couplings A_f via polarisation in sfermion decays, (ii) the impact of complex MSSM parameters on the third generation sfermion decays, (iii) determination of CP violation in the complex MSSM via T-odd asymmetries in neutralino production and decay, and (iv) an analysis of the chargino and neutralino mass parameters at one-loop level.
Data from the LHC at 7, 8, and 13 TeV have so far yielded no evidence for new particles beyond the 125 GeV Higgs boson; in particular, there have been no signs of SUSY. However, the complementary nature of physics with $e^+e^-$ collisions still offers many interesting scenarios in which SUSY can be discovered at the ILC. These scenarios take advantage of the capability of $e^+e^-$ collisions to observe events with missing four-momentum -- a signature not available at hadron colliders, where only transverse imbalance is observable. Due to low backgrounds and trigger-less operation, detectors at…
We perform a complete analysis of the supersymmetric particle spectrum in the Minimal Supergravity (mSUGRA) model where the soft SUSY breaking scalar masses, gaugino masses and trilinear couplings are unified at the GUT scale, so that the electroweak symmetry is broken radiatively. We show that the present constraints on the Higgs boson and superparticle masses from collider searches and precision measurements still allow for large regions of the mSUGRA parameter space where charginos, neutralinos, sleptons and top squarks as well as the heavier Higgs particles, are light enough to be produced…
SUSYGEN is a Monte Carlo program designed for computing distributions and generating events for MSSM sparticle production in e+ e- collisions. The Supersymmetric (SUSY) mass spectrum may either be supplied by the user, or can alternatively be calculated in two different models of SUSY Breaking: gravity mediated supersymmetry breaking (SUGRA), and gauge mediated supersymmetry breaking (GMSB). The program incorporates the most important production processes and decay modes, including the full set of R-parity violating decays, and the decays to the gravitino in GMSB models. Initial state radiatio…
We report a next-to-leading order (NLO) calculation of the production of gaugino-like charginos ($\chargino$) and neutralinos ($\neutralino$) in association with gluinos ($\gluino$) at hadron colliders, including the strong corrections from colored particles and sparticles. We predict inclusive cross sections at the Fermilab Tevatron and CERN LHC. The NLO cross sections are more stable against variations in the hard-scattering scale parameter and are greater than the LO values.
In the Minimal Supersymmetric Standard Model, physical phases of complex parameters lead to CP violation. We show how triple products of particle momenta or spins can be used to construct asymmetries, that allow us to probe these CP phases. To give specific examples, we discuss the production of neutralinos at the International Linear Collider. For the Large Hadron Collider, we discuss CP asymmetries in squark decays, and in the tri-lepton signal. We find that the CP asymmetries can be as large as 60%.
We study the effects of O(alpha_s) supersymmetric QCD (SQCD) corrections on the total production rate and kinematic distributions of polarized and unpolarized top-pair production in pp and p anti-p collisions. At the Fermilab Tevatron p anti-p collider, top-quark pairs are mainly produced via quark-antiquark annihilation, q anti-q -> t anti-t, while at the CERN LHC pp collider gluon-gluon scattering, g g -> t anti-t, dominates. We compute the complete set of O(alpha_s) SQCD corrections to both production channels and study their dependence on the parameters of the Minimal Supersymmetric Standa…
We investigate the ability of single top quark production via qq'-> squark->tb and q \bar q'->slepton->t\bar b at the LHC and Tevatron to probe the strength of R-parity violating couplings in the minimal supersymmetric model. We found that given the existing bounds on R-parity violating couplings, single top quark production may be greatly enhanced over that predicted by the standard model, and that both colliders can either discover R-parity violating SUSY or set strong constraints on the relevant R-parity violating couplings. We further found that the LHC is much more powerful than the Tevat…
CP violation in the decays $t \to \ell^+νb$ and $\bar t \to \ell^-\barν\bar b$ from the production process $e^-e^+ \to \ttbar$ is discussed. Since the asymmetry proposed as a measure of CP violation vanishes even at the one-loop level in the Standard Model (SM), it may be a useful tool to search for sources of CP violation outside of the SM. As an illustration the asymmetry has been computed within supersymmetric extensions of the SM. Prospects for its measurement at future high-energy linear colliders are discussed.
We discuss the potential of combined analyses at the Large Hadron Collider and the planned International Linear Collider to explore low-energy supersymmetry in a difficult region of the parameter space characterized by masses of the scalar SUSY particles around 2 TeV. Precision analyses of cross sections for light chargino production and forward--backward asymmetries of decay leptons and hadrons at the ILC, together with mass information on chi^0_2 and squarks from the LHC, allow us to determine the underlying fundamental gaugino/higgsino MSSM parameters and to constrain the masses of the heav…
More than 30 years ago, Arnowitt-Chamseddine-Nath (ACN) and others established the compelling framework of supergravity gauge theories (SUGRA) as a picture for the next step in beyond the Standard Model physics. We review the current SUGRA scenario in light of recent data from LHC8 collider searches and the Higgs boson discovery. While many SUSY and non-SUSY scenarios are highly disfavored or even excluded by LHC, the essential SUGRA scenario remains intact and as compelling as ever. For naturalness, some non-universality between matter and Higgs sector soft terms is required along with substa…
We correct our treatment of decays of the lightest chargino to final states containing the lightest neutralino in the case where the chargino and neutralino masses differ by less than 1 GeV. A brief summary of the phenomenological implications is given.
We investigate the sparticle production processes $eγ\goto \sele\sz1$ and $γγ\goto \sfermion\overline{\sfermion}$ at high energy $eγ$ and $γγ$ colliders in the framework of the minimal supersymmetric standard model (MSSM). It will be shown that the $eγ$ colliders would be more suitable in searching for the heavy selectrons than $ee$ colliders because of the low mass threshold of the process $eγ\goto \sele\sz1$. We show that the standard background processes $eγ\goto νW$ and $eZ$ can be suppressed in terms of initial beam polarization as well as the kinematical cuts on the energy and angle of t…
We present a complete analysis of threshold resummation effects on direct light and heavy gaugino pair production at the Tevatron and the LHC. Based on a new perturbative calculation at next-to-leading order of SUSY-QCD, which includes also squark mixing effects, we resum soft gluon radiation in the threshold region at leading and next-to-leading logarithmic accuracy, retaining at the same time the full SUSY-QCD corrections in the finite coefficient function. This allows us to correctly match the resummed to the perturbative cross section. Universal subleading logarithms are resummed in full m…
Combined analyses at the Large Hadron Collider and at the International Linear Collider are important to reveal precisely the new physics model as, for instance, supersymmetry. Examples are presented where ILC results as input for LHC analyses could be crucial for the identification of signals as well as of the underlying model. The synergy of both colliders leads also to rather accurate SUSY parameter determination and powerful mass constraints even if the scalar particles have masses in the multi-TeV range.
Discussions are underway for a high-energy proton-proton collider. Two preliminary ideas are the $\sqrt{s}=33$ TeV HE-LHC and the $\sqrt{s}=100$ TeV VLHC. With Bayesian statistics, we calculate the probabilities that the LHC, HE-LHC and VLHC discover SUSY in the future, assuming that nature is described by the CMSSM and given the experimental data from the LHC, LUX and Planck. We find that the LHC with $300$/fb at $\sqrt{s}=14$ TeV has a $15$-$75%$ probability of discovering SUSY. Should that run fail to discover SUSY, the probability of discovering SUSY with $3000$/fb is merely $1$-$10%$. Wer…
We systematically calculate various flavor-changing neutral-current top-quark processes induced by supersymmetry at the Large Hadron Collider, which include five decay modes and six production channels. To reveal the characteristics of these processes, we first compare the dependence of the rates for these channels on the relevant supersymmetric parameters, then we scan the whole parameter space to find their maximal rates, including all the direct and indirect current experimental constraints on the scharm-stop flavor mixings. We find that, under all these constraints, only a few channels, th…